With rapid development of computer technology, a variety of electronic devices have been widely used, and have become important tools in people's daily work and life. In order to facilitate data transmission among the electronic devices, people have designed for the electronic devices various types of data transmission interfaces, among which a USB (Universal Serial Bus) interface is a very common data transmission interface.
As technologies develop, there have been diverse types of USB interfaces, among which a micro USB interface, used in a mobile device such as a cellphone, a tablet PC or the like in particular, is a very common type of USB interface. A Type C USB interface is a most recently-developed USB interface and will replace the micro USB interface in the future. In the coming days, devices with the Type C USB interface and devices with the micro USB interface will exist in the market concurrently. Conversion cables for the Type C USB interface and the micro USB interface may provide data transmission for the devices having the two different interfaces. In such conversion cables, an identity (ID) pin of the micro USB interface is generally connected to a CC1 pin (a pin in the Type C USB interface) or a CC2 pin (a pin in the Type C USB interface) of the Type C USB interface.
In some devices having the Type C USB interface, the CC1 pin and a VBUS (power supply) pin are coupled to each other via a resistor. A voltage of the VBUS is generally 5V, and a normal working voltage of the ID pin of the micro USB interface should be 1.8V. Thus, for the device having the Type C USB interface, when it is connected to a device having the micro USB interface via a conversion cable, the device having the micro USB interface may be damaged.